Since several years, attempts have been made to provide slides for vehicles seats which, while exhibiting a large resistance, enable on the one hand to adapt a safety belt on the seat itself and on the other hand to obtain, when a frontal or lateral impact occurs, a reduction of the forces produced by the deformation and if necessary the destruction of said slides, thereby avoiding too serious wounds to passengers seated on the seat.
Moreover, it is necessary that the rack and motor assemblies can be used practically on several types of vehicles with very small modifications of detail, at the most a change of location of holes on the upper mobile sections in order to enable the manufacturer to easily fix the seat frame.
These parameters as a whole require therefore a thorough study from the viewpoint of the production costs as well as of the resistance and possibilities of universal adaptation.
According to the invention, the screw slide system is controlled manually or by an electrical, pneumatic , oleopneumatic , hydraulic, magnetic or other motor and comprises a gear-down mechanism rigidly connected to one of the upper sections of the system which also comprises a fixed lower section having on its inner face a toothing forming a rack and separated from the upper section by members facilitating a sliding of the two sections with respect to each other, and is characterized in that:
(a) reversible endless screws, mounted on a shaft which can rotate freely with respect to the rack, are connected by a train of gears on the one hand to a power transfer box rigidly connected to the gear-down mechanism, and by angle transmissions on the other hand to a balancing shaft for the rotation of the endless screws in order to enable the two sections to work in conjunction in order to displace the seat attached on said slide system,
(b) these endless screws are blocked in the position chosen for the seat by shoes with inclined upper sections normally pressed against each other by springs and unlocked by the flat portions of a bar the rotation of which is controlled manually or in an imperative manner by an electrical, pneumatic, oleopneumatic, hydraulic, magnetic or other motor, the displacement of the seat being manual.
According to another feature of the invention, the gear-down mechanism and the power transfer box are disposed: the first transversely and the second longitudinally with respect to the vehicle axis.
Various other features of the invention will become more apparent from the following detailed description.